Global plant oil production exceeded 120 metric tons (MT) in 2009, and continues to be dominated by four main oil crops: palm, soybeans, rapeseed or canola, and sunflowers (Wilson and Hildebrand, 2010). Indeed, world-wide palm and soybean production has increased rapidly in recent years, with rapeseed also showing steady increases, and it is expected that this trend will only continue as the projected global oil production in 2010 was expected to climb to over 170 million MT.
Of the oil being produced from the four main oil crops, palm oil production has been dominated by Malaysia and Indonesia, while the vast majority of soybeans are produced in the United States, Brazil, China and Argentina. Despite the production of different oils by different countries, however, global oilseed production has been consistently dominated by soybeans and has been followed by rapeseed as a distant second (Wilson and Hildebrand, 2010). Over 200 million MT of soybean seeds have been produced in recent years, and this dominance is believed to be because, among oilseeds, soybeans are low in oil and high in protein making soybeans the dominant global protein source. On average, soybeans consist of approximately 20% oil and 40% protein on a dry weight basis, whereas rapeseed is approximately 50% oil and palm fruit is close to 90% oil and includes both palm fruit oil and kernel oil.
Breeding for increased oilseed yield per unit land area has also continued to progress in recent years with steady soybean yield increases being a good example (Egli, 2008a; Egli, 2008b). This increased yield is often with little or no increased inputs, thus making renewable oil production from plants less expensive over time and, at the same time, more competitive with petroleum as an industrial chemical feedstock. Indeed, while most plant oil continues to be produced and used for food purposes, an increasing proportion of plant oil is being utilized for industrial uses, with the proportion of industrial versus food usage having increased from approximately 10% to approximately 20% in the last 10 years.
Because U.S. and global seed and oil production is extensive and important for the both the production of oils for human and animal consumption and for industrial purposes, the value of even a 3-5% increase in seed oil content is also significant and has been increasingly recognized. Accordingly, a method of increasing oil content by only a small percentage would be both desirable and beneficial. More specifically, a method of increasing renewable oil production in a plant that is not accompanied by a concomitant decrease in protein levels in the plant, would be highly desirable and beneficial not only for purposes of human consumption, but also from an industrial perspective.